What is the Concept of energy neutral Waste Water Treatment Plants?
Resource recovery in wastewater treatment is becoming more and more important. It's also possible, thanks to new technology.
Historically, the interaction of water and energy has been considered in relation to the region or technology. And at the national and international levels, water and energy systems have been independently developed, managed and regulated. But recently, the world has recognized that water and energy are not only related, but closely related. It's time we all need water and energy and need to participate in efforts to secure them for the next generation.
What are the important things to consider?
Water reuse, policies and partnerships, and new disruptive technology solutions are important to the cause. In particular, there is an urgent need to change the perspective of wastewater treatment and switch to sustainable strategic infrastructure solutions.
Wastewater treatment plants are not waste treatment plants, but by producing renewable energy, they produce clean water, regenerate nutrients (such as phosphorus and nitrogen), and recover resources that may reduce their dependence on fossil fuels.
EPA recognizes energy as the second highest budget item for municipal drinking water and sewerage systems after labour costs, with utilities spending about billions annually on energy. The energy consumption of drinking water and sewerage systems can account for 30-40 percent of the municipality's total energy tariff.
Netsol Water is a highly regulated company whose main purpose is to meet regulatory requirements to protect public health and the environment at reasonable and fair prices.
Previously, energy efficiency was not at the top of the list of priorities. However, given population growth and stricter environmental regulations, electricity demand for water and sanitation will increase by about 20 percent, according to the EPA. With the rise in electricity prices, energy saving and efficiency are becoming more and more important for households in local governments.
A road to energy neutral Wastewater Treatment
The continued impact of the global recession puts an additional financial burden on wastewater companies as they strive to meet increasingly stringent drainage requirements in aging infrastructure that needs to be repaired and replaced.
Energy conservation, on-site power generation, and renewables are becoming increasingly important to wastewater companies as energy policies, energy management, and measures to curb climate change converge with the need to meet higher standards for wastewater treatment. Many utilities are beginning to reduce energy consumption on the grid at their facilities through a variety of energy-saving and on-site energy generation measures. Combining new disruptive innovations with operational practices will focus on the potential for energy-neutral wastewater treatment.
How is this energy produced?
Energy is produced in the field by extracting the energy content of organic matter in wastewater and converting them into usable forms. For example, anaerobic digestion and bio-waste treatment systems use bacteria in the absence of oxygen to break down organic matter and produce biogas. Biogas can then be burned or oxidized to be used for heating or to generate electricity and heat in a gas engine. It can also be compressed and used as fuel for vehicles or sold for use in natural gas networks.
You can also use additional nutrient-rich sewage as fertilizer. The advanced anaerobic digestion system is designed to recycle bio-solids into methane and valuable by-products, which is key to a cheap and maintenance-free way to convert sludge into electricity.
This technology can also be used to treat food waste, bio-waste such as fat/oil (FOG). Combining the digestion of these external organic sources with the digestion of organic matter in bio-solids from wastewater treatment can significantly increase the energy production potential of wastewater treatment plants. Cities with a population of 500,000 generate approximately 75,000 tonnes of household and commercial food waste and more than 14,000 tonnes of sewage sludge.
The greatest energy requirement for wastewater treatment is to supply oxygen to the biological system. This is usually achieved by forced ventilation. In fact, about 60% of the energy in wastewater treatment plants is used for ventilation. To achieve energy-neutral and ultimately net wastewater treatment, plants need low-energy treatment to replace traditional ventilation, as well as ways to improve energy production in existing infrastructure.